THE LATEST from the Left Coast: Bill Simon has taken out radio ads attacking Arnold Schwarzenegger, who reportedly will start running TV ads as early as Wednesday. On the Democratic side, Democratic Lt. Gov. Cruz Bustamante, also a candidate to replace Gray Davis, claims that the governor’s henchmen are trying to squelch donations to his campaign. Davis, meanwhile, has received an unexpected boost–more like a testosterone shot–from an unlikely source: the actress Cybill Shepherd, who bared her soul to the San Francisco Chronicle.